Antenna element and display device

Abstract

An antenna element and a display device are provided. The antenna element according to an exemplary embodiment includes a dielectric layer; and an antenna pattern formed in a mesh structure on the dielectric layer and including an irregularly shaped edge.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0037953, filed on March 24, 2021, with the Korean Intellectual Property Office (KIPO), the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to an antenna element and a display device. Background Technology

[0004] Recently, with the development of the information society, wireless communication technologies such as Wi-Fi and Bluetooth have been implemented in the form of smartphones by combining with display devices. In this case, an antenna can be coupled to the display device to perform communication functions.

[0005] Recently, as mobile communication technologies have become more advanced, there is a need to couple antennas used for communication in high-frequency or ultra-high-frequency bands with display devices. Furthermore, with the development of thin, highly transparent, and high-resolution display devices such as transparent and flexible displays, there is a need to develop antennas that also offer improved transparency and flexibility.

[0006] As the screen size of display devices with antennas increases, the space or area of ​​the bezel or light-shielding portion has been reduced. In this case, the space or area where the antenna can be embedded may also be limited.

[0007] Therefore, it is necessary to design an antenna that can radiate signals with high antenna gain in a limited space without being seen by the user. Summary of the Invention

[0008] The purpose of this invention is to provide an antenna element and a display device including the antenna element.

[0009] To achieve the above objectives, the present invention adopts the following technical solution.

[0010] 1. An antenna element comprising: a dielectric layer; and an antenna pattern formed on the dielectric layer in a mesh structure and including irregularly shaped edges.

[0011] 2. According to the antenna element of 1 above, the shape of the edge depends on the position and shape of the outermost cell forming the antenna pattern.

[0012] 3. According to the antenna element in 2 above, the size and shape of the outermost cell are the same as those of the other cells.

[0013] 4. According to the antenna element in 2 above, the size and shape of the outermost cell are different from those of the other cells.

[0014] 5. The antenna element according to 1 above, wherein the antenna pattern includes: a radiator; and a transmission line extending from the radiator.

[0015] 6. The antenna element according to 5 above further includes: a signal pad connected to one end of the transmission line; and a grounding pad disposed around the signal pad.

[0016] 7. According to the antenna element of 6 above, the signal pad and the ground pad are formed as solid structures.

[0017] 8. The antenna element according to 1 above further includes a dummy pattern disposed around the antenna pattern, thereby being electrically and physically separated from the antenna pattern.

[0018] 9. A display device comprising an antenna element according to claim 1.

[0019] An antenna element according to an exemplary embodiment may include a non-flat portion formed on the outer periphery of an antenna pattern. This non-flat portion includes a plurality of recesses and protrusions, which may be formed irregularly or randomly on the outer periphery of the antenna pattern. Thus, antenna performance can be maintained and the pattern's visibility to the user can be reduced using the antenna element ("pattern visibility"). Attached Figure Description

[0020] The above and other objects, features, and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 This is a schematic cross-sectional view showing an antenna element according to an exemplary embodiment;

[0022] Figure 2 This is a schematic plan view illustrating an antenna element according to an exemplary embodiment;

[0023] Figure 3A and Figure 3B This is an antenna element according to an exemplary embodiment. Figure 2 Enlarged images of parts "A" and "B" in the image;

[0024] Figure 3C and Figure 3D This is an antenna element according to another exemplary embodiment. Figure 2 Enlarged images of parts "A" and "B" in the image;

[0025] Figure 3E and Figure 3FThis is an antenna element according to another exemplary embodiment. Figure 2 Enlarged images of parts "A" and "B" in the image;

[0026] Figures 3G to 3I This is an antenna element according to another exemplary embodiment. Figure 2 An enlarged view of part of the letter "A" in the image;

[0027] Figure 4 This is a schematic plan view illustrating a display device according to an exemplary embodiment;

[0028] Figure 5A and Figure 5B It is based on a comparative example of an antenna element. Figure 2 Enlarged images of parts "A" and "B" in the image;

[0029] Figure 6 and Figure 7 This is a view showing the antenna performance evaluation results of the antenna elements prepared in the embodiments and comparative examples; and

[0030] Figure 8A and Figure 8B This is a view showing the evaluation results of the pattern visibility of the antenna elements prepared in the embodiments and comparative examples. Detailed Implementation

[0031] In the following, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, since the accompanying drawings are provided merely to illustrate one of several preferred embodiments of the invention in order to readily understand the technical spirit of the invention having the above-described contents, they should not be construed as limiting the description shown in the drawings.

[0032] The antenna element described in this invention can be a microstrip patch antenna fabricated as a transparent thin film. For example, this antenna element can be applied to electronic devices for high-frequency or ultra-high-frequency (e.g., 3G, 4G, 5G, or higher) mobile communications, Wi-Fi, Bluetooth, near-field communication (NFC), global positioning system (GPS), etc., but is not limited thereto. Here, electronic devices can include mobile phones, smartphones, tablets, laptops, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, MP3 players, digital cameras, wearable devices, etc. Wearable devices can include watch-type, wristband-type, ring-type, belt-type, necklace-type, ankle-type, thigh-strap-type, forearm-strap-type, etc. However, electronic devices are not limited to the above examples, and wearable devices are not limited to the above examples. Furthermore, the antenna element can be applied to various objects or structures, such as vehicles and buildings.

[0033] In the following figures, two directions parallel to the upper surface of the dielectric layer and intersecting each other perpendicularly are defined as the x-direction and the y-direction, and the direction perpendicular to the upper surface of the dielectric layer is defined as the z-direction. For example, the x-direction may correspond to the width direction of the antenna element, the y-direction may correspond to the length direction of the antenna element, and the z-direction may correspond to the thickness direction of the antenna element.

[0034] Figure 1 This is a schematic cross-sectional view showing an antenna element according to an exemplary embodiment.

[0035] Reference Figure 1 According to an exemplary embodiment, the antenna element 100 may include a dielectric layer 110 and an antenna patterning layer 120.

[0036] The dielectric layer 110 may include an insulating material having a predetermined dielectric constant. According to one embodiment, the dielectric layer 110 may include an inorganic insulating material such as glass, silicon oxide, silicon nitride, or metal oxide, or an organic insulating material such as epoxy resin, acrylic resin, or imide resin. The dielectric layer 110 may serve as a thin-film substrate on which the antenna pattern layer 120 is formed in the antenna element 100.

[0037] According to one embodiment, the transparent film can be configured as the dielectric layer 110. In this case, the transparent film may include: polyester resins, such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, etc.; cellulose resins, such as diacetylcellulose, triacetylcellulose, etc.; polycarbonate resins; acrylic resins, such as poly(meth)acrylate, poly(ethyl methacrylate), etc.; styrene resins, such as polystyrene, acrylonitrile-styrene copolymer, etc.; polyolefin resins, such as polyethylene, polypropylene, cyclic polyolefins or polyolefins having a norbornene structure, ethylene-propylene copolymer, etc.; vinyl chloride resins; amide resins, such as nylon, aromatic polyamides; imide resins; polyether sulfonic acid resins; sulfonic acid resins; polyether ether ketone resins; polyphenylene sulfide resins; vinyl alcohol resins; vinylidene chloride resins; vinyl butyral resins; allyl compounds; polyoxymethylene resins; thermoplastic resins, such as epoxy resins, etc. These compounds may be used alone or in combination of two or more. In addition, a transparent film made of thermosetting resins or UV-curable resins such as (meth)acrylates, urethanes, urethane acrylates, epoxy resins, and silicones can be used as the dielectric layer 110.

[0038] According to one embodiment, the dielectric layer 110 may also include an adhesive film such as optically transparent adhesive (OCA) or optically transparent resin (OCR).

[0039] According to one embodiment, the dielectric layer 110 can be formed as a basic single layer or as a multilayer structure with two or more layers.

[0040] Capacitance or inductance can be generated through dielectric layer 110, thereby adjusting the frequency band that antenna element 100 can drive or sense. When the dielectric constant of dielectric layer 110 exceeds approximately 12, the driving frequency is excessively reduced, which may prevent antenna driving at the desired high frequency band. Therefore, according to one embodiment, the dielectric constant of dielectric layer 110 can be adjusted to a range of approximately 1.5 to 12, preferably approximately 2 to 12. Furthermore, according to one embodiment, dielectric layer 110 can be formed with a thickness of 4 μm to 1000 μm, allowing antenna element 100 to be driven at the desired high frequency band. However, this is not a limitation, and the dielectric constant and thickness of dielectric layer 110 can be varied according to the desired frequency band.

[0041] According to one embodiment, the insulating layer (e.g., the encapsulation layer, passivation layer, etc. of the display panel, etc.) inside the display device on which the antenna element 100 is mounted can be configured as a dielectric layer 110.

[0042] The antenna pattern layer 120 can be disposed on the upper surface of the dielectric layer 110.

[0043] The antenna pattern layer 120 may include a low-resistance metal, such as silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), tin (Sn), molybdenum (Mo), calcium (Ca), or an alloy comprising at least one of these. These may be used alone or in combination of two or more. For example, the antenna pattern layer 120 may include silver (Ag) or a silver alloy (e.g., a silver-palladium-copper (APC) alloy) to achieve low resistance. As another example, considering low resistance and fine linewidth patterning, the antenna pattern layer 120 may include copper (Cu) or a copper alloy (e.g., a copper-calcium (CuCa) alloy).

[0044] According to one embodiment, the antenna pattern layer 120 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), zinc oxide (ZnOx), or copper oxide (CuO).

[0045] According to one embodiment, for example, the antenna pattern layer 120 may include a stacked structure of a transparent conductive oxide layer and a metal layer, and may have a two-layer structure of transparent conductive oxide layer-metal layer or a three-layer structure of transparent conductive oxide layer-metal layer-transparent conductive oxide layer. In this case, the metal layer can be used to reduce resistance to improve signal transmission speed and simultaneously improve flexibility, and the transparent conductive oxide layer can be used to improve corrosion resistance and transparency.

[0046] According to one embodiment, the antenna pattern layer 120 can be blackened. For example, the surface of the antenna pattern layer 120 can be thermally oxidized to reduce reflectivity. Therefore, the visibility of the pattern due to light reflection from the surface of the antenna pattern layer 120 can be reduced.

[0047] The surface portion of the metal layer of the antenna pattern layer 120 can be blackened to form a blackened layer in which a portion of the metal layer is made of metal oxide or metal sulfide. Alternatively, a blackened layer can be formed on the metal layer, such as a coating of a black material, a plating of metals such as nickel and chromium, etc.

[0048] The blackening layer is used to improve the transparency and visibility of the metal layer by reducing its reflectivity, and may include, for example, at least one of silicon oxide, metal oxide, copper, molybdenum, carbon, tin, chromium, nickel and cobalt.

[0049] The composition and thickness of the blackening layer can be adjusted in various ways according to the desired degree of blackening.

[0050] The following will refer to Figure 2 Figure 3 illustrates the specific details of the antenna pattern layer 120.

[0051] According to one embodiment, the antenna element 100 may further include a ground plane 130. Because the antenna element 100 includes a ground plane 130, vertical radiation characteristics can be achieved.

[0052] Ground layer 130 may be disposed on the lower surface of dielectric layer 110. Ground layer 130 may overlap with antenna pattern layer 120 with a dielectric layer 110 in between. For example, ground layer 130 may overlap with the radiator of antenna pattern layer 120 (see [reference]). Figure 2 211) completely overlap.

[0053] According to one embodiment, the conductive component of the display device or display panel on which the antenna element 100 is mounted can be configured as a ground layer 130. For example, the conductive component may include electrodes or wiring, such as the gate electrode, source / drain electrode, pixel electrode, common electrode, data line, scan line, etc. of a thin-film transistor (TFT) included in the display panel; and the stainless steel (SUS) plate, heat sink, digitizer, electromagnetic wave shielding layer, pressure sensor, fingerprint sensor, etc. of the display device.

[0054] Figure 2 This is a schematic plan view illustrating an antenna element according to an exemplary embodiment. Figure 3A and Figure 3B This is an antenna element according to an exemplary embodiment. Figure 2 Enlarged images of parts "A" and "B" in the image; Figure 3C and Figure 3D This is an antenna element according to another exemplary embodiment. Figure 2 Enlarged images of parts "A" and "B" in the image; Figure 3E and Figure 3F This is an antenna element according to another exemplary embodiment. Figure 2 Enlarged images of parts "A" and "B" in the text; and Figures 3G to 3I This is an antenna element according to another exemplary embodiment. Figure 2 An enlarged view of part of the "A" in the image.

[0055] Reference Figure 2 As shown in FIG. 3, an antenna element 100 according to an exemplary embodiment includes an antenna pattern layer 120 disposed on a dielectric layer 110, and the antenna pattern layer 120 may include an antenna pattern 210.

[0056] The antenna pattern 210 may include the aforementioned metal or alloy and may be formed into a mesh structure. The mesh structure may include multiple cells 310 defined by multiple conductors 311. Each cell 310 may include an outermost cell 310b and the remaining cells 310a excluding the outermost cell 310b. Because the antenna pattern 210 is formed into a mesh structure, the light transmittance of the antenna pattern 210 can be increased, and the flexibility of the antenna element 100 can be improved. Therefore, the antenna element 100 can be effectively applied to flexible display devices.

[0057] Antenna pattern 210 may include irregularly shaped edges 320. For example, edges 320 may be formed along the edges of the outermost cells 310b of antenna pattern 210. Therefore, the shape of edges 320 may depend on the position and shape of the outermost cells 310b of antenna pattern 210. In this case, the size and shape of the outermost cells 310b are the same as those of the remaining cells 310a (see [link to relevant documentation]). Figures 3A to 3F ), or their size and / or shape differ from the rest of the cells 310a except for them ( Figures 3G to 3I ).

[0058] For example, such as Figure 3A and Figure 3B As shown, cell 310 can have a diamond shape. In this case, the outermost cell 310b and the remaining cells 310a can have the same size and shape as each other.

[0059] In another example, such as Figure 3C and Figure 3D As shown, cell 310 can be C-shaped or inverted C-shaped. In this case, the outermost cell 310b and the remaining cells 310a can have the same size and shape. Here, the C-shape or inverted C-shape can be a shape in which the top and bottom edges are straight lines that are parallel to each other and the left and right edges are curves that are parallel to each other.

[0060] In another example, such as Figure 3E and Figure 3F As shown, cell 310 can have a rectangular shape. In this case, the outermost cell 310b and the remaining cells 310a can have the same size and shape as each other.

[0061] In another example, such as Figure 3G As shown, cell 310 can have a diamond shape. In this case, the outermost cell 310b and the remaining cells 310a can have different sizes and shapes. For example, the spacing between the outermost cell 310b and the remaining cells 310a can be different.

[0062] In another example, such as Figure 3H As shown, cell 310 can be C-shaped or inverted C-shaped. In this case, the outermost cell 310b and the remaining cells 310a can have different sizes and shapes. For example, the spacing between the outermost cell 310b and the remaining cells 310a can be different.

[0063] In another example, such as Figure 3IAs shown, cell 310 can have a rectangular shape. In this case, the outermost cell 310b and the remaining cells 310a can have different sizes and shapes. For example, the spacing between the outermost cell 310b and the remaining cells 310a can be different.

[0064] According to an exemplary embodiment, since the edge 320 of the antenna pattern 210 is formed in an irregular shape, the pattern can be significantly reduced or suppressed from being seen by the user when the antenna pattern 210 is placed in the display area of ​​the display device (e.g., the area where visual information is displayed).

[0065] Antenna pattern 210 may include radiator 211 and transmission line 212.

[0066] The radiator 211 can receive electrical signals from the transmission line 212, convert them into electromagnetic wave signals, and radiate the converted electromagnetic wave signals.

[0067] The shape and size of the radiator 211 can be determined according to the desired resonant frequency, radiation resistance, and gain. According to an exemplary embodiment, the radiator 211 may have a polygonal plate shape.

[0068] The transmission line 212 can be formed to extend from the radiator 211. For example, the transmission line 212 can be formed to have a length of 0.5 mm to 7.0 mm, thereby driving the antenna element 100 at the desired high frequency band. However, it is not limited to this, and the length of the transmission line 212 can be varied according to the desired frequency band.

[0069] According to one exemplary embodiment, the transmission line 212 may be integrally connected to the radiator 211 to form a substantially single component, or it may be formed as a component separate from the radiator 211.

[0070] According to one exemplary embodiment, the transmission line 212 may be formed as a mesh structure having a substantially the same shape as the radiator 211 (e.g., having the same line width, the same cell size, etc.), but is not limited thereto, and may also be formed as a mesh structure having a substantially different shape from the radiator 211.

[0071] The antenna pattern layer 120 may also include a signal pad 220.

[0072] Signal pad 220 can be connected to one end of transmission line 212, thereby electrically connecting it to radiator 211 via transmission line 212. According to an exemplary embodiment, signal pad 220 can be integrally connected to transmission line 212 to form a substantially single component, or it can be formed as a component separate from transmission line 212. For example, signal pad 220 can be formed as a substantially integral component with transmission line 212, and the end portion of transmission line 212 can be configured as signal pad 220.

[0073] According to one exemplary embodiment, signal pad 220 can be electrically connected to a driving circuit unit (e.g., a radio frequency integrated circuit (RFIC)). For example, a flexible printed circuit board (FPCB) can be bonded to signal pad 220, and the circuit wiring of the FPCB can be electrically connected to signal pad 220. For example, anisotropic conductive film (ACF) bonding technology can be used to electrically connect signal pad 220 to FPCB, which is a bonding method that uses anisotropic conductive film (ACF) or coaxial cable to achieve vertical conductivity while horizontal insulation, but is not limited thereto. The driving circuit unit can be mounted on the FPCB or a separate printed circuit board (PCB) to be electrically connected to the circuit wiring of the FPCB. Therefore, signal pad 220 and driving circuit unit can be electrically connected to each other.

[0074] The antenna pattern layer 120 may also include a grounding pad 230.

[0075] Grounding pad 230 can be disposed around signal pad 220. For example, a pair of grounding pads 230 can be disposed facing each other with signal pad 220 in between. Grounding pad 230 can be electrically and physically separated from signal pad 220 and transmission line 212 around signal pad 220.

[0076] According to an exemplary embodiment, considering factors such as reduced power supply resistance and noise absorption efficiency, the signal pad 220 and the ground pad 230 can be formed as solid structures made of the aforementioned metal or alloy.

[0077] The antenna pattern layer 120 may also include a dummy pattern 240.

[0078] A dummy pattern 240 may be disposed around the antenna pattern 210 to be electrically and physically isolated from the antenna pattern 210. For example, the separation region may be formed along the outer conductor or non-flat portion 320 of the antenna pattern 210 to separate the dummy pattern 240 from the antenna pattern 210.

[0079] According to one exemplary embodiment, the dummy pattern 240 may include the same metal or alloy as the antenna pattern 210, and may be formed as a mesh structure having a substantially the same shape as the antenna pattern 210. According to one embodiment, the dummy pattern 240 may be formed as a mesh structure, wherein a portion of the conductors forming the dummy pattern 240 is cut off.

[0080] According to this exemplary embodiment, the antenna element 100 includes an antenna pattern 210 having a non-flat portion 320 and a dummy pattern 240 disposed around the antenna pattern 210, such that when the antenna element 100 is applied to a display device, the pattern can be significantly reduced or suppressed from being seen by the user.

[0081] at the same time, Figure 2 An example of antenna element 100 including an antenna pattern 210 is shown, but it is not limited thereto. For example, antenna element 100 may include multiple antenna patterns arranged in an array on dielectric layer 110. According to an exemplary embodiment, when antenna element 100 includes multiple antenna patterns, the radiator size of each antenna pattern may be different from each other. In this case, antenna element 100 may be configured as a multi-band antenna operating in multiple resonant frequency bands.

[0082] Figure 4 This is a schematic plan view illustrating a display device according to an exemplary embodiment. More specifically, Figure 4 It is a view showing the outline of a window containing a display device.

[0083] Reference Figure 4 The display device 400 may include a display area 410 and an outer peripheral area 420.

[0084] The display area 410 can represent the area for displaying visual information, and the outer peripheral area 420 can represent the opaque areas disposed on both sides and / or at both ends of the display area 410. For example, the outer peripheral area 420 can correspond to the light-shielding portion or the bezel portion of the display device 400.

[0085] According to one embodiment, the antenna element 100 described above can be mounted on the display device 400. For example, the antenna pattern 210 of the antenna element 100 can be configured to at least partially correspond to the display area 410, and the signal pad 220 and the ground pad 230 can be configured to at least partially correspond to the outer peripheral area 420.

[0086] The FPCB or PCB can be disposed together with the drive circuit unit (e.g., RFIC) in the outer peripheral region 420. By positioning the signal pad 220 of the antenna element 100 close to the drive circuit unit, signal loss can be suppressed by shortening the path used for transmitting and receiving signals.

[0087] Antenna element 100 includes an antenna pattern 210 and / or a dummy pattern 240 formed in a mesh structure, which can improve light transmittance and significantly reduce or suppress the pattern from being seen by the user. Therefore, the image quality in display area 410 can also be improved while maintaining or improving the desired communication reliability.

[0088] Test case

[0089] form Figure 2 The two antenna elements are shown. In this case, one antenna element is formed to have Figure 3A and Figure 3B The edge of the antenna pattern shown (in an embodiment), while another antenna element is formed with Figure 5A and Figure 5B The edge of the antenna pattern shown (comparative example).

[0090] Then, tests are conducted to evaluate the antenna performance of the antenna elements prepared in the embodiments and comparative examples, and the results can be obtained. Figure 6 and Figure 7 The evaluation results are shown in Figure 8. As a result of evaluating pattern visibility, the results are shown in Figure 8.

[0091] Reference Figure 6 and Figure 7 It can be seen that the electromagnetic wave radiation patterns in the antenna elements of the comparative example and the embodiment are similar to those of S11. Furthermore, referring to FIG8, it can be seen that... Figure 8B In the case of the antenna element in the embodiment shown, with Figure 8A The antenna element in the comparative example shown has reduced pattern visibility.

[0092] That is, it can be seen that the antenna element according to the embodiment is superior to the antenna element according to the comparative example in terms of pattern visibility, while maintaining the same antenna performance as the antenna element according to the comparative example.

[0093] The present invention has been described with reference to the preferred embodiments described above, and those skilled in the art will understand that various modifications can be made without departing from the essential characteristics of the invention. Therefore, it should be understood that the scope of the invention is not limited to the embodiments described above, and various embodiments within the scope equivalent to that of the claims are also included in the invention.

Claims

1. An antenna element, characterized in that, It includes: Dielectric layer; as well as An antenna pattern is formed on the dielectric layer in a mesh structure, the mesh structure comprising multiple cells defined by multiple conductors. The edge of the antenna pattern is formed along the edge of the outermost cell among the plurality of cells. The shape of the edge of the antenna pattern depends on the position and shape of the outermost cell, and the outermost cell is not arranged regularly but randomly, resulting in an irregular pattern for the edge of the antenna pattern. The outermost cell has the same size and shape as all other cells except the outermost cell.

2. The antenna element according to claim 1, characterized in that, The antenna pattern includes: Radiators; and Transmission lines extending from the radiator.

3. The antenna element according to claim 2, characterized in that, It also includes: A signal pad, which is connected to one end of the transmission line; and A grounding pad is disposed around the signal pad.

4. The antenna element according to claim 3, characterized in that, The signal pad and the grounding pad are formed as a solid structure.

5. The antenna element according to claim 1, characterized in that, It also includes a dummy pattern disposed around the antenna pattern, thereby being electrically and physically separated from the antenna pattern.

6. A display device, characterized in that, It includes the antenna element according to claim 1.

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